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EXFO FTB-8500 Series for FTB-500 User Manual

Page 281

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IPTV Tabs

Ethernet and Fibre Channel Application

267

Overview

DF (ms): The Delay Factor (DF) provides a measure of the maximum
packet delay variation over a period of 1 second. In other words, the
metric presents in milliseconds how much buffer would be required in
the next downstream network element to compensate for the media
packet jitter. Note that by definition (as detailed in RFC 4445) a DF
value representing a minimum of one line packet (in ms) is reported
when no jitter exists in the network. This represents the minimum
buffer size (in ms) required to properly process a media packet and
this value changes depending on the media rate of the stream. For
example, if no jitter exists in the network, a typical Standard Television
stream with a media rate of 3.75 Mbps would exhibit a Delay Factor of
2.81 ms while for a High Definition Television stream of 10 Mbps the
Delay Factor would be 1.05 ms.

MLR (pps): Indicates the count of lost packets in the last second
(packets per second) as per RFC 4445, out-of-order and duplicate are
considered lost packets.

TR 101 290: By default this column presents the PCR Jitter value. If any
of the supported TR 101 290 alarm occurs then the alarm temporarily
replaces the PCR Jitter. Supported TR 101 290 alarms are PCR Jitter, TS
Sync Loss
, Sync Byte Error, PAT Error2, CC Error, PMT Error2, PID
Error Video
, and PID Error Audio.

PCR Jitter (ms): Indicates the maximum absolute difference between
a known reference and the PCR value decoded from the MPEG-2
Transport Stream packets in the last second.

IP Rate (Mbps): Indicates the number of IP bits received in the last
second (Mbps).

BW (%) (Bandwidth): Indicates the Ethernet bandwidth utilization of
the stream.

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